Respirator



' Dec. 29, 1936.

F. WAHLERT 2,065,775

RESPIRATOR Filed April 4, 1935 2 Sheets-Sheet 1 INVENTOR.

ZREOE/P/C/r WIHL ER 7.-

ATTORNEYS F. WAHLERT Dec. 29, 1936.

RESPIRATOR Filed April 4, 1935 2 Sheets-Sheet 2 7 WWW W ATTORNEYS Patented Dec. 29, 1936 UNITED STATES PATENT I OFFICE 2,065,775 linsrma'roa Application April 4, 1935, Serial No. 14,571

3 Claims. 01. 183-44) This invention relates to improvements in respirators and in particular to a novel form of pouch adapted to be removably secured to. the shell of a respirator, the pouch being interchangeable with conventional types of filtering means commonly used with respirators. The improved pouch provides a large breathing area for the wearer and offers a relatively low resistance to the entrance of air.

In its more detailed aspects, the invention aims to provide a pouch which can make an easy swiveled connection with attachment sleeves which secure it to the respirator shell. A further feature relates to the provision of improved means for holding the main elements of the pouch in a distended condition. Further features relate to the improved combination and arrangement of parts more fully hereinafter shown, described and claimed.

20 In the drawings- I Fig. 1 is a side elevation of a respirator embodying the invention; Fig. 2 is a front elevation thereof; Fig. 3 is a view partly in side elevation and partly in section on theline 3-3 of 25 Fig. 2; Fig. 4 is a perspective detail view showing the improved pouch connected with the screw shell used to detachably secure the same to a -respirator; Fig. 5 is a perspective view of parts shown in Fig. 4 prior to their assembly; Fig. 6 is an enlarged detail view illustrating the means for positively holding the main elements of the pouch distended; Fig. 7 is a side view partly in section illustrating a modification, wherein a swiveled connecting sleeve is permanently secured to the pouch; Figi 8 is an enlarged. detail illustrating a further modification of the swiveled connection between the pouch body and attachment shell.

40 Referring in detail to the drawings, l6 represents the metallic body of a known type-of respirator which is' usually equipped with a face engaging cushion i2 and an exhaling valve l4 and suitable head strap l6. At its forward end,

45 the respirator is usually equipped with a screw threaded sleeve l8 which bears against a gasket 20, an inner annular flange 22 being bent over to secure the sleeve l8 fixedly to the hollow body Ill.

50 The sleeve I8 is provided with screw threads 24 and at its outer extremity is formed with an inwardly directed flange 26. The parts thus far described in detail are of conventional construction and the sleeve I8 is adapted in some types 55 of respirators to engage with a screw threaded member carrying filter pads, screens, medicated sponges or the like.

In my improved respirator, instead of using filter pads, sponges or similarexpedients which are of a size approximating that of the sleeve 5 I8, I provide a pouch, indicated generally at 28, which is formed of inner and outer plies 30 and 32, respectively, of relatively thick felt joined at' the periphery by a marginal line of stitching 34. The pouch has sewed to the inner ply 30 thereof, 10 an annular ring 36 of felt. The outer diameter of this ring is approximately equal to the external diameter of the sleeve l8. A circular line of stitching 38 unites the ring 36 to the inner ply of the pouch, as clearly shown in Fig. 3. A

threaded attaching shell 40 is provided which has an inwardly extending flange 42 which is arranged to lie between the outer face of the ply 30 and the adjacent face of the felt ring 36. The central opening defined by the flange 42 is slightly smaller than the outside diameter of the felt ring 36 and the ring is assembled therewith by slightly puckering or collapsing the same and permitting it to expand and thus become impositively united with the attaching shell 40.

The thus united parts are shown as a unit in Fig. 4 while Fig. 5 shows the parts separated. When the parts are assembled, as in Fig. 4, the pouch is in condition to be attached to the respirator by merely turning the shell 40 and thus screwing it onto the threads 24 of the sleeve l8. After the parts are screwed home to the position in Fig. 2, the pouch may be swiveled so that the broadest part thereof is located at the bottom. This provides a convenient and comfortable disposition of the parts and one which does not interfere with the wearers vision, nor does it objectionably interfere with the balance of theparts, as would be the case if there were a long forwardly extending part, or if there were a part materially higher than the screw shell.

I deem it important to provide positive means for holding the plies or walls 30 and 32 in spaced relationship so as to provide an interior chamber 44 whose size cannot be varied by the inadvert- 45 ent collapsing of the pouch, such as when. it is struck by a foreign object or when the wearer may fall to the ground.

In Fig. 6, the means for holding the walls of the pouch distended are illustrated as comprising a post 46 having a head 48 which engages the outer surface of the ply' 32. This post carries a washer 50 which makes a fairly snug fit therewith and coacting with this washer, there is a second cupped washer 52. These washers are assembled by exerting a pressure thereon, in such a manner that the inner edge 54 of the central opening of the washer 52 bites or digs into the metal of the post 46. At the end of the post remote from the head 48, the same is shouldered down and screw threaded, as shown at 56 and an interior washer 58 bears on the shoulder formed on the post and a nut 60 having a relatively large head for engagement with the outer face of the ply 30 of the pouch is threaded onto the shank 56 and screwed down tight so as to firmly clamp the material to said ply 30 between the head of the nut and the inside washer 58.

In the modified form of the invention exemplified in Fig. 7, I do away with the felt ring 36 such as shown in Fig. 5. In this modification, the coupling shell 40 is swiveled to a grommet 62 having a relatively large diameter annular flange 64 which engages the inner surface of the wall 30 of the pouch. This grommet has another flange 66 which overlaps the inwardly extending flange 42 formed on the shell 40.

A further modification of the manner of swiveling the pouch to the detaching sleeve is illustrated in Fig. 8. In this figure, the grommet 62 secured to the ply 30 of the pouch engages an inner flange of an annular ring 68. This ring is also formed with an outwardly extending flange,

the two flanges being joined by a substantially and the pouch. In the various constructions shown, the nested flange parts are assembled by the use of suitable ties which press the flanges into the positions illustrated.

The walls or plies 30 and 32 of the pouch, as illustrated in the enlarged detail view Fig. 6, are of a special type of felt having an outer strata ID of wool felt which is relatively more dense than the remaining portion. This relative density or porosity provides a better filter surface andone which is peculiarly well suited for preventing the entrance of impalpable powder-like substances through the walls of the pouch.

While the invention has been described in considerable detail, it is to be understood that various modifications and substitutions of equivalents may be made by those skilled in the art without departure from the invention as defined in the appended claims.

What I claim is:-

1. A respirator pouch, the walls of which comprise relatively flat bodies of felt 'whose outer strata are of greater density than their inner strata.

2. A- respirator poubh comprising two pieces of felt joined at their marginal edges, each piece having outer strata of greater density than its inner strata.

3. A respirator' pouch of the character described comprising a complementary pair of felt pieces stitched together at their marginal edges, each of said pieces having an outer wool felt 

